Light emitting devices used in illumination devices, display devices, and traffic signals are required to have high optical output and long lifetime. Semiconductor light emitting devices have longer lifetime than conventional bulb light sources and are suitable for these applications.
In a semiconductor light emitting device, fine uneven structures may be provided on the surface of the semiconductor layer on the light emitting surface side. Such fine uneven structures can increase the light extraction efficiency from the semiconductor to the outside and improve the optical output. However, the uneven structures provided on the semiconductor surface may decrease the adhesiveness between the semiconductor light emitting device and the sealing resin provided thereon. In a resin-sealed semiconductor light emitting device, the difference in linear expansion coefficient between the semiconductor and the resin due to heat generation of the light emitting device induces a stress. This stress acts in the direction of peeling the resin from the semiconductor surface. Hence, a gap generated between the semiconductor device and the resin due to decreased adhesiveness lowers the optical output. Thus, there is demand for a semiconductor light emitting device capable of increasing the adhesiveness between the semiconductor surface and the resin to suppress peeling, thereby improving reliability.